Angiogenesis is a part of adult wound healing, which starts from inflammation and may end in scarring. When inflammation, angiogenesis, and scarring are well controlled, adult wound healing results in the restoration of tissue function. In contrast, pathologic angiogenesis that is frequently associated with uncontrolled inflammation may lead to pathologic scarring. In the eye, where vision is the key function, any such scar-prone wound healing can lead to blindness. In fact, the NIH has recognized that the inability of chronic wounds to heal is a major health problem in the United States and that such a problem will increase in magnitude as the population ages. We have long speculated that one novel solution to the aforementioned problem lies in a better understanding of the biological function of the fetal membrane, which consists of the amniotic membrane (AM) and the chorion (CH). Our speculation is derived partly from cumulative clinical successes of AM transplantation in delivering anti-inflammatory, anti- scarring, and anti-angiogenic efficacies to the ocular surface, as well as from the mystery of fetal wound healing that lacks inflammation and angiogenesis, and is "scarless". We have successfully purified the covalent HC"HA complex formed between hyaluronan (HA) and the heavy chain (HC) of inter- -inhibitor (I I) from the AM and has identified it as one active component that exerts anti-inflammatory, anti-scarring and anti-angiogenic actions. We have further gathered strong evidence supporting that HC"HA purified from the CH is 25 fold more potent than that purified from the AM and that PTX3 from the CH may enhance the HC"HA's suppression of vascular endothelial proliferation. In this Phase I application, we thus propose to delineate the chemical structure of HC"HA by verifying that PTX3 is indeed the key protein from CH to enhance HC"HA's anti-angiogenic action (Aim 1);and to characterize and compare the in vitro anti-angiogenic action of HC"HA purified from the CH to that from AM (Aim 2). Together with the study to be supported by a Phase II (R44 EY017497) grant, which focuses on testing in vivo anti-inflammatory and anti-scarring efficacies by HC"HA purified from the AM, we believe that successful completion of the above two aims will let us put forth a novel therapeutic paradigm, for the first time, where a single HC"HA complex can simultaneously curtail three key steps, i.e., inflammation, angiogenesis, and scarring of adult wound healing. As a result, we envision that HC"HA may not only be an embryonic matrix responsible for ensuring scarless fetal wound healing, but it can also be sufficiently harnessed from the fetal membrane as a novel biomaterial, from which we may launch new therapeutics to gear adult wound healing towards regeneration. By including PTX3 to HC"HA, we may develop a new class of angiogenesis inhibitors for treating many diseases in and beyond ophthalmology where pathologic angiogenesis threatens our vision and health. PUBLIC HEALTH RELEVANCE: The research described in this Phase I application is aimed at developing a novel class of angiogenesis inhibitors that are based on the covalent HC"HA complex formed between hyaluronan (HA) and the heavy chain (HC) of inter- -inhibitor and purified from the fetal membrane, i.e., the amniotic membrane and the chorion. Our proposed research intends to prove that PTX3, a pentraxin family member known to exert both anti-angiogenic and anti- inflammatory actions, first, is strongly associated with HC"HA purified from the chorion and, second, is responsible for enhancing the anti-angiogenic potency of HC"HA. We believe that PTX3 can be added to HC"HA to produce a new class of angiogenesis inhibitors, which will not only suppress angiogenesis mediated by bFGF and VEGF but will also be more useful and effective by curtailing additional inflammation and scarring. Consequently, we may develop new therapeutics based on PTX3 bound to HC"HA to treat many diseases in and beyond ophthalmology where unwanted angiogenesis is detrimental to our vision and health.